Crowds of revelers swarmed South Bay beaches on the Fourth of July and kept lifeguards busy on the Monday holiday but caused no major problems, officials said.

Police officers fielded a battery of calls through the night Sunday and arrested people for fireworks possession and alcohol-related incidents, but reported no major incidents.

Manhattan Beach police Sgt. Christian Eichenlaub said it was unexpectedly slow in the city.

“It was so quiet I left early,” Eichenlaub said. “There were a lot of people down there but nothing worth mentioning.”

Hermosa Beach Sgt. Don Jones said officers arrested people for drug possession and fighting, but had no big problems other than rowdy crowds. Even the annual Ironman competition – in which participants compete by running a mile, paddling in the ocean for a mile and chugging a six-pack of beer on the beach – was relatively low-key, he said.

“We had a lot of party calls,” Jones said. “I would say it was a little bit busier than last year.

“We had a lot of rescues – typical riptide rescues because the surf is up,” Yamamoto said. “Every year it’s a triple threat of crowds, sunshine and heavy surf. This year we had heavy surf and heavy crowds. The sunshine broke later but it didn’t matter.”

Local cities reported a lot of illegal fireworks use but few arrests and citations.

Los Angeles police Lt. John Pasquariello of the Harbor Division station said extra officers were patrolling the San Pedro and Wilmington areas for illegal activity on Sunday.

“We have a few neighborhoods with historically major fireworks events, and we saturated those areas to ensure safety,” Pasquariello said. “We had a few arrests for illegal fireworks. We wanted to make a statement. We want people to understand this is serious.”

In Inglewood, a garage burned in a fire at Beach Street and West 64th Place about 11:10 p.m. Saturday, a county fire dispatcher said.

Investigators were trying to determine whether fireworks touched off the blaze, which was put out in about 15 minutes. No one was injured, officials said.